#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define mp make_pair
const int maxn = 1e5+10;
const int mod = 1e9+7;
const int INF = 0x3f3f3f3f;
int d[4][2]={1,0,0,1,-1,0,0,-1};
int main() {
    ios::sync_with_stdio(0);
    string s;
    cin>>s;
    if(s=="ABC"){
        cout<<"ARC";
    }else{
        cout<<"ABC";
    }
    return 0;
}